1. Field of the Invention
This invention relates to an information processing apparatus for performing data processing by starting an operating system (OS) stored in a read-only memory (ROM) or an OS read from a secondary storage unit.
2. Description of the Related Art
Heretofore, in this kind of information processing apparatus, when using an OS stored in a ROM, a memory map for a ROM, a RAM (random access memory) and the like has been mostly configured as shown in FIG. 4.
On the other hand, when using an OS loaded from a secondary storage unit, such as a floppy disk or the like, without using an OS stored in the ROM, a memory map has been configured as shown in FIG. 5.
In FIGS. 4 and 5, there are shown a space 51 which can be utilized by the user, an OS area 52 within the ROM, and an area 53 for BOOT processing within the ROM, such as a BOOT program and the like. A loaded OS area 54 is an area occupied by an OS loaded from the secondary storage unit using the BOOT program.
In the state shown in FIG. 5, although the OSs are present in both the OSROM 52 and the loaded OS 54, what is actually used is the loaded OS. The OSROM 52 uselessly occupies the address space, and hence memory resources have not been effectively utilized.
In this kind of information processing apparatus, a method has been proposed which selects whether a BIOS (basic input/output system) is to be allocated to a ROM or to a RAM. In this case, however, in order to indicate the selection of the ROM or the RAM, hardware, such as a DIP switch and the like, and dedicated software for processing the hardware have been necessary.